Conduction Mechanism and Improved Endurance in HfO₂-Based RRAM with Nitridation Treatment

A nitridation treatment technology with a urea/ammonia complex nitrogen source improved resistive switching property in HfO₂-based resistive random access memory (RRAM). The nitridation treatment produced a high performance and reliable device which results in superior endurance (more than 10⁹ cycles) and a self-compliance effect. Thus, the current conduction mechanism changed due to defect passivation by nitrogen atoms in the HfO₂ thin film. At a high resistance state (HRS), it transferred to Schottky emission from Poole-Frenkel in HfO₂-based RRAM. At low resistance state (LRS), the current conduction mechanism was space charge limited current (SCLC) after the nitridation treatment, which suggests that the nitrogen atoms form Hf-N-Ox vacancy clusters (V_o⁺) which limit electron movement through the switching layer.